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[Federal Register Volume 63, Number 135 (Wednesday, July 15, 1998)]
[Proposed Rules]
[Pages 38120-38122]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-18777]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-51-AD]
RIN 2120-AA64

Airworthiness Directives; Boeing Model 767 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Boeing Model 767 series 
airplanes. This proposal would require detailed visual inspections to 
detect corrosion or chrome plating cracks on the fuse pins, load 
distribution plates, and bushings of the outboard support of the main 
landing gear (MLG) beam. This proposal also would require either 
installation of the existing fuse pins and repetitive inspections; or 
installation of newer-type fuse pins, which would constitute 
terminating action for the repetitive inspections. This proposal is 
prompted by a report indicating that corrosion was found on a fuse pin 
in the outboard support of the MLG beam. The actions specified by the 
proposed AD are intended to detect and correct such corrosion and 
cracking, which could result in the failure of a fuse pin and, 
consequently, lead to collapse of the MLG.

DATES: Comments must be received by August 31, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 97-NM-51-AD, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056. Comments may be inspected at this location 
between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal 
holidays.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: James G. Rehrl, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington; telephone (425) 227-2783; 
fax (425) 227-1181.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 97-NM-51-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 97-NM-51-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received a report of corrosion on a fuse pin in the 
outboard support of the main landing gear (MLG) beam on a Boeing Model 
767 series airplane. At the time the corrosion was detected, the 
airplane had accumulated 23,637 total flight hours and 5,652 total 
flight cycles. Investigation revealed that the chrome plating on the 
fuse pin did not have a sufficient bond to the base metal, which 
allowed the chrome plate to crack and peel from the base metal. This 
cracking in the chrome plate allowed moisture to accumulate in the 
subject area and, consequently, caused corrosion on the base metal of 
the fuse pin. Such cracking and corrosion, if not detected and 
corrected, could result in

[[Page 38121]]

failure of a fuse pin and, consequently, lead to collapse of the MLG.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
767-57A0054, Revision 2, dated April 18, 1996, which describes 
procedures for detailed visual inspections to detect corrosion or 
chrome plating cracks on the fuse pins of the outboard support of the 
MLG beam. The alert service bulletin also describes procedures for 
either installation of existing 4330M steel fuse pins and repetitive 
detailed visual inspections; or installation of newer-type 15-5PH CRES 
fuse pins, which would eliminate the need for the repetitive 
inspections. The alert service bulletin also describes procedures for 
inspections of the load distribution plates and fuse pin bushings to 
detect corrosion. These latter parts make up a portion of the MLG 
outboard support fitting assembly into which the fuse pins are 
installed. Accomplishment of the actions specified in the alert service 
bulletin is intended to adequately address the identified unsafe 
condition.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require accomplishment of the actions specified in 
the alert service bulletin described previously, except as discussed 
below.

Differences Between the Proposed Rule and the Relevant Service 
Information

    Operators should note that, although the alert service bulletin 
specifies that the manufacturer may be contacted for disposition of 
certain repair conditions, this proposal would require that the repair 
of those conditions to be accomplished in accordance with a method 
approved by the FAA.
    Also, whereas the alert service bulletin uses the term ``close 
visual inspection,'' this proposal uses the more common term ``detailed 
visual inspection.'' For the purpose of this proposal, the two terms 
are considered to be synonymous.

Cost Impact

    There are approximately 609 Boeing Model 767 series airplanes of 
the affected design in the worldwide fleet. The FAA estimates that 151 
airplanes of U.S. registry would be affected by this proposed AD, that 
it would take approximately 4 work hours per airplane to accomplish the 
proposed actions, and that the average labor rate is $60 per work hour. 
Based on these figures, the cost impact of this proposed AD on U.S. 
operators is estimated to be $36,240, or $240 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the proposed requirements of 
this AD action, and that no operator would accomplish those actions in 
the future if this AD were not adopted.

Regulatory Impact

    The regulations proposed herein would not have substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, will not have a significant economic impact, 
positive or negative, on a substantial number of small entities under 
the criteria of the Regulatory Flexibility Act. A copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (14 CFR part 39) as 
follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Boeing: Docket 97-NM-51-AD.
    Applicability: Model 767 series airplanes, line numbers 1 
through 609 inclusive, certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (e) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To detect and correct cracking and corrosion of the fuse pins, 
load distribution plates, and bushings in the outboard support of 
the main landing gear (MLG) beam, which could result in the failure 
of a fuse pin and, consequently, lead to collapse of the MLG, 
accomplish the following:
    (a) Within 4 years of service since the MLG was new, or within 
18 months after the effective date of this AD, whichever occurs 
later, perform detailed visual inspections of the fuse pins of the 
MLG outboard support beam to detect corrosion or chrome plating 
cracks on the fuse pin, and of the load distribution plates and 
bushings of the MLG outboard support beam to detect corrosion; in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 767-57A0054, Revision 2, dated April 18, 1996.
    (b) If any corrosion or plating crack of a fuse pin is found 
during any inspection required by paragraph (a) of this AD, prior to 
further flight, accomplish either paragraph (b)(1) or (b)(2) of this 
AD.
    (1) Install a new or serviceable 4330M steel fuse pin in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 767-57A0054, Revision 2, dated April 18, 1996. 
Repeat the detailed visual inspections required by paragraph (a) of 
this AD thereafter at intervals not to exceed 48 months. Or
    (2) Install a newer-type 15-5PH CRES fuse pin in accordance with 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
767-57A0054, Revision 2, dated April 18, 1996. Accomplishment of 
this installation constitutes terminating action for the repetitive 
inspection requirements of paragraphs (a), (b)(1), and (d)(1) of 
this AD.
    (c) If any corrosion of a load distribution plate or bushing is 
found during any inspection required by paragraph (a) or (b) of this 
AD, prior to further flight, repair in accordance with a method 
approved by the Manager, Seattle Aircraft Certification Office 
(ACO), FAA, Transport Airplane Directorate.
    (d) If no corrosion or plating crack is found on the fuse pins, 
load distribution plates, or bushings, prior to further flight, 
accomplish the requirements of either paragraph (d)(1) or (d)(2) of 
this AD in accordance with the Accomplishment Instructions of Boeing 
Alert

[[Page 38122]]

Service Bulletin 767-57A0054, Revision 2, dated April 18, 1998.
    (1) Install the existing 4330M steel fuse pins in accordance 
with the Accomplishment Instructions of the alert service bulletin. 
Repeat the detailed visual inspections required by paragraph (a) of 
this AD thereafter at intervals not to exceed 48 months. Or
    (2) Install newer-type 15-5PH CRES fuse pins in accordance with 
the Accomplishment Instructions of the alert service bulletin. 
Accomplishment of this installation constitutes terminating action 
for the repetitive inspection requirements of paragraphs (a), 
(b)(1), and (d)(1) of this AD.
    (e) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Seattle ACO. Operators shall submit 
their requests through an appropriate FAA Principal Maintenance 
Inspector, who may add comments and then send it to the Manager, 
Seattle ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

    (f) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.

    Issued in Renton, Washington, on July 8, 1998.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-18777 Filed 7-14-98; 8:45 am]
BILLING CODE 4910-13-P
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